ÌâÄ¿ÄÚÈÝ

12£®2015Äê12ÔÂ27ÈÕÈ«¹úÈË´ó³£Î¯»á»áÒéͨ¹ýÁ˹ØÓÚÐ޽̿ÚÓë¼Æ»®ÉúÓý·¨µÄ¾ö¶¨£¬¡°È«Ãæ¶þº¢¡±´Ó2016ÄêÔªµ©Æð¿ª¸øÊµÊ©£®AÊи¾ÁªÎªÁ˽â¸ÃÊÐÊÐÃñ¶Ô¡°È«Ãæ¶þº¢¡±Õþ²ßµÄ̬¶È£¬Ëæ»ú³éÈ¡ÁËÄÐÐÔÊÐÃñ45ÈË¡¢Å®ÐÔÊÐÃñ55È˽øÐе÷²é£¬µÃµ½ÒÔÏÂ2¡Á2ÁÐÁª±í£®
  Ö§³Ö·´¶Ô ºÏ¼Æ 
ÄÐÐÔ 30 15 45
 Å®ÐÔ 45 10 55
 ºÏ¼Æ 75 25 100
£¨1£©¸ù¾ÝÒÔÉÏÊý¾Ý£¬ÄÜ·ñÓÐ90%µÄ°ÑÎÕÈÏΪAÊÐÊÐÃñ¡°Ö§³ÖÈ«Ãæ¶þº¢¡±Óë¡°ÐÔ±ð¡±Óйأ¿
£¨2£©ÏÖ´Ó²ÎÓëµ÷²éµÄÅ®ÐÔÓû§Öа´·Ö²ã³éÑùµÄ·½·¨Ñ¡³ö11Ãû·¢·ÅÀñÆ·£¬ÔÚËù³éÈ¡µÄ11ÈËÖзֱðÇó³ö¡°Ö§³Ö¡±ºÍ¡°²»Ö§³Ö¡±Ì¬¶ÈµÄÈËÊý£»
£¨3£©½«ÉÏÊöµ÷²éËùµÃµ½µÄƵÂÊÊÓΪ¸ÅÂÊ£¬ÏÖÔÚ´ÓAÊÐËùÓÐÊÐÃñÖУ¬²ÉÈ¡Ëæ»ú³éÑùµÄ·½·¨³éÈ¡3λÊÐÃñ½øÐг¤ÆÚ¸ú×Ùµ÷²é£¬¼Ç±»³éÈ¡µÄ3λÊÐÃñÖг֡°Ö§³Ö¡±Ì¬¶ÈÈËÊýΪX£®
¢ÙÇóXµÄ·Ö²¼ÁУ»
¢ÚÇóXµÄÊýѧÆÚÍûE£¨X£©ºÍ·½²îD£¨X£©£®
¸½±í¼°¹«Ê½£º
 P£¨K2¡Ýk0£© 0.150.10 0.05 0.025 0.010 
 k0 2.0722.7063.841 5.024 6.635 
K2=$\frac{n£¨ad-bc£©^2}{£¨a+b£©£¨c+d£©£¨a+c£©£¨b+d£©}$£¬ÆäÖÐn=a+b+c+d£®

·ÖÎö £¨1£©¼ÆËãK2£¬Óë2.706±È½Ï´óС£»
£¨2£©¸ù¾Ý¸÷²ãµÄÈËÊý±ÈÀý¼ÆË㣻
£¨3£©Çó³öXµÄ·Ö²¼ÁУ¬´úÈ빫ʽ¼ÆËãÊýѧÆÚÍûºÍ·½²î£®

½â´ð ½â£º£¨1£©K2=$\frac{100£¨30¡Á10-45¡Á15£©^{2}}{45¡Á55¡Á75¡Á25}$¡Ö3.0303£®
¡ß3.0303£¾2.706£¬
¡àÓÐ90%µÄ°ÑÎÕÈÏΪAÊÐÊÐÃñ¡°Ö§³ÖÈ«Ãæ¶þº¢¡±Óë¡°ÐÔ±ð¡±Óйأ®
£¨2£©11¡Á$\frac{45}{10+45}$=9£¬11¡Á$\frac{10}{45+10}=2$£®
ËùÒÔÔÚËù³éÈ¡µÄ11ÈËÖзֱð¡°Ö§³Ö¡±Ì¬¶ÈµÄÈËÊýΪ9£¬¡°²»Ö§³Ö¡±Ì¬¶ÈµÄÈËÊýΪ2£®
£¨3£©¢ÙÊÐÃñ³ÖÖ§³Ö̬¶ÈµÄ¸ÅÂÊΪ$\frac{3}{4}$£¬²»Ö§³Ö̬¶ÈµÄ¸ÅÂÊ$\frac{1}{4}$£¬
XµÄȡֵΪ0£¬1£¬2£¬3£®
ÓÚÊÇP£¨X=0£©=£¨$\frac{1}{4}$£©3=$\frac{1}{64}$£¬P£¨X=1£©=${C}_{3}^{1}$¡Á$\frac{3}{4}¡Á£¨\frac{1}{4}£©^{2}$=$\frac{9}{64}$£¬P£¨X=2£©=${C}_{3}^{2}$¡Á£¨$\frac{3}{4}$£©2¡Á$\frac{1}{4}$=$\frac{27}{64}$£¬P£¨X=3£©=£¨$\frac{3}{4}$£©3=$\frac{27}{64}$£®
¡àËæ»ú±äÁ¿XµÄ·Ö²¼ÁÐΪ£º

X0123
P $\frac{1}{64}$ $\frac{9}{64}$ $\frac{27}{64}$ $\frac{27}{64}$
¢ÚXµÄÊýѧÆÚÍûE£¨X£©=0¡Á$\frac{1}{64}+1¡Á\frac{9}{64}+2¡Á\frac{27}{64}+3¡Á\frac{27}{64}$=$\frac{9}{4}$£®
XµÄ·½²îD£¨X£©=$\frac{1}{64}¡Á£¨-\frac{9}{4}£©^{2}$+$\frac{9}{64}¡Á£¨1-\frac{9}{4}£©^{2}$+$\frac{27}{64}¡Á£¨2-\frac{9}{4}£©^{2}$+$\frac{27}{64}¡Á£¨3-\frac{9}{4}£©^{2}$=$\frac{9}{16}$£®

µãÆÀ ±¾Ì⿼²éÁ˶ÀÁ¢ÐÔ¼ìÑ飬·Ö²ã³éÑù£¬Ëæ»ú±äÁ¿·Ö²¼£¬ÊôÓÚÖеµÌ⣮

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø